Radiologic evaluation of the solitary pulmonary nodule

The SPN is a common radiologic finding. The advent of low-dose screening chest CT increases the likelihood that these lesions will need to be dealt with in the future. There are different management approaches and the work-up can often require evaluation over a long period of time to establish a benign or malignant diagnosis. Comparison with old examinations and morphologic evaluation of the size, margins, and internal characteristics of a SPN should be the first step in the evaluation of these lesions. It is often necessary, however, to proceed to additional imaging techniques, such as CT or PET, and in some situations invasive tests, such as transthoracic needle aspiration or surgical biopsy, may be required.